Hemodynamic Changes and Hemorrhage Risk in Arteriovenous Malformations Following Endovascular Embolization: A Matched Case-Control Study

Introduction: Endovascular embolization is an increasingly popular treatment strategy for cerebral arteriovenous malformations (AVMs), but the treatment procedure is highly individualized and may carry a higher risk of hemorrhage in specific cases. Hemodynamic changes are believed to influence AVM rupture and treatment outcomes. This study aimed to investigate hemodynamic changes and risk factors associated with hemorrhage after embolization in AVMs.

Methods: This matched case-control study analyzed data from the MATCH registry. Patients undergoing single-session endovascular embolization between August 2011 and December 2021 were included. Hemodynamic parameters were measured before and after embolization using quantitative digital subtraction angiography. Univariable logistic regression assessed associations between hemodynamic changes and hemorrhage, with subgroup analyses for intraoperative and delayed hemorrhage.

Results: Among 3909 AVM patients in the registry, 217 met the eligibility criteria, including 18 with hemorrhage and 199 without. After matching, 36 patients (18 in each group) were analyzed. Baseline characteristics were similar across groups. After the embolization, the feeding artery stasis index significantly increased in the hemorrhage group, with both absolute (OR 2.41, 95% CI 1.12–5.20; AUC=0.765) and relative changes (OR 12.37, 95% CI 1.32–115.75; AUC=0.750) strongly associated with hemorrhage. Intraoperative hemorrhage was linked to feeding artery hemodynamics (increased stasis index and time to peak, and decreased outflow gradient), while delayed hemorrhage was associated with nidus hemodynamics (increased inflow and outflow gradient).

Conclusion : Increased feeding artery stasis index post-embolization was significantly associated with hemorrhage in AVMs. Intraoperative hemorrhage was primarily related to changes in feeding artery hemodynamics, while delayed hemorrhage was linked to nidus hemodynamics.